Trends in seasonal influenza and H1N1 vaccine uptake using Colorado Behavioral Risk Factor Surveillance System (BRFSS) data

Background: Widespread use of influenza vaccine is a crucial intervention for control of influenza transmission. We analyzed Colorado Behavioral Risk Factor Surveillance System (CO-BRFSS) data to identify trends in influenza vaccine uptake based on demographics, health characteristics and CDC target groups. Methods: Using real- time data from CO-BRFSS from September through December 2009, weighted means and confidence intervals were calculated for these responses: 1) Did you receive any seasonal influenza vaccine (SIV) in the past year? 2) Did you receive any H1N1 vaccine since September 2009? Results were stratified to compare demographic or health characteristics among vaccine recipients. Results: Among SIV vaccinees, only 24.1% were aged 18-29 years, while 32.8% were 30-49 years and 48.3% were 50-69 years. More SIV recipients were college graduates (51.8%) than those with less than high school education (19.8%). Marked differences existed among SIV recipients having health insurance (45.3%) versus no insurance (12.5%). Persons vaccinated with SIV frequently had underlying conditions including heart disease (63.3%), diabetes (57.7%) or asthma (46.9%). H1N1 vaccinees showed similar trends as SIV except that persons aged 18-29 years had comparable representation as persons 50-69 years (5.9% versus 5.3% respectively) and a higher proportion of H1N1 vaccinees had annual income under $15,000 (9.1%) compared to over $50,000 (5.5%). Conclusion: A population-based survey can be used to assess emergent issues, such as H1N1. Public health campaigns may have successfully increased uptake of H1N1 vaccine in young adults as compared to SIV. Socioeconomic factors and access to healthcare influences who receives influenza vaccine.